Semiconductors generally require many measurement processes for their manufacture. For example, a CD (critical dimension) measurement step for measuring line widths of micro patterns formed on a semiconductor substrate is required for the manufacture of a semiconductor. In CD measurement, line widths of a resist pattern used in a photolithographic step, line widths of wirings and trench widths or trench widths formed in an etching step, and so on, are measured. A CD measuring device measures portions of a semiconductor substrate with electron beams while monitoring them in an enlarged scale.
The image of a certain measuring portion, which is monitored by a CD measure, is typically used for analysis of defects. For analysis of defects, the image is digitally converted and stored as image data. To find causes of the defects early, it is desirable that the image data is of a high quality.
However, the higher the quality of the image data, the larger the volume of the image data. In case the volume of the image data is large, it takes a long time to digitally convert, input or output the image data, write or read the image data, and so forth. As a result, semiconductor processing devices such as CD measures take a long time to process the semiconductor substrate. This means that semiconductor processing devices degrade in throughput. This results in increasing the cycle time of the semiconductor manufacturing process and hence increasing the manufacturing cost of semiconductor elements.
FIG. 11 shows a graph that exhibits changes of the throughput of a semiconductor processing device and the time for analysis of defects relative to volumes of image data. FIG. 11 shows such changes schematically for better understanding.
According to FIG. 11, the larger the volume of image data, the higher the quality of the image and the shorter the time required for analysis of its defects. On the other hand, the larger the volume of the image data, the longer the throughput time of the semiconductor processing device.
That is, there is a trade off between the time required for analysis of defects and the throughput of the semiconductor processing device in relation to the volume of the image data. It is needed to digitally convert individual images to image data files that are different from each other in terms of data volume or file format in order to attain equilibrium between the time required for analysis of defects and the throughput time of the semiconductor processing device.
In general, the measuring condition in CD measurement includes information about the data volume of image data upon digital conversion. Therefore, the measuring condition must be modified to change the information about the data volume of the image data.
However, after executing measurement according to a certain measurement condition, it is difficult and troublesome to continue the measurement by changing the file format in the measuring condition and the data volume.
Conventionally, therefore, it was difficult to digitally convert individual images to image data files different from each other in data volume or file format.
Under the circumstances, there is a demand for a semiconductor processing device, semiconductor processing system and semiconductor processing management method capable of digitally converting individual images to image data files different from each other in volume or file format.